Carburetor



Aug. M1923.

G. B. MAEGLY CARBURETOR Filed Jan. l0 1917 2 Sheets-Sheet l AMJ Nm, mw

w@ hw [rave/fof 0607?@ B, Magg@ Patented Aug, 2l, i923,

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GEORGE B. MAEGLY, OF lKANSAS CITY, IVIISSOURI, ASSIGNOR TO -STROMBERG MOTOR DEVICES COMPANY, .0F CHICAGO, ILLINOIS,- A CORPORATION OF ILLINOIS.-

CRBURE'IOR.

Application led January-1l), 1917-v Serial No. 1411,671.l

To all whom it may concern:

Be it known that I, GEORGE B.VMAEGILY,

a citizen of the United States,` residing at Kansas City, in the county of Jackson and State of Missouri', have invented a certain new and useful Improvement in Carburetors,'of which the following is a full, clear, concise, and exact description,4 reference being had to the accompanying drawings, formino* a part of this specification.

My invention relates .to ca rburetors for internal combustion engines contemplates an improved device, the, purpose of which is to regulate the proportion of fuel and air for various engine conditions and to secure a better quality of mixture than has :leretofore been possible.

My invention contemplates a positive fuel control governed .by the `sub-normal` pressure of the engine side-of the throttle, referred to conveniently as the side above the throttle, the fuel, of course, and the air being admitted below the throttle. Furtliermore, my invention contemplates, as part of the combination, meansforsecuring an increment of fuel upon engine acceleration and it will be seen that the means which I provide is particularly and peculiarly adapted to the fundamental and underlying principle from which my invention proceeds.

The arrangement. which I propose also lends itself particularly and peculiarly to an operators control for getting the minimum fuel on low running and for limitingthe maximum fuel on high running.

A further feature of my invention lies in the operators control of the air passage ,from the atmosphere to the engine whereby there is provided `not only an eflicient choking device for `starting purposes, but also a regulator for suction effect on thefuel inlet during subsequent running. i

In the preferred form ofp-my invention, I do away entirely with the v common float chamber of the prior art, thus greatly simplifying the structure, reducing the number of moving parts, and at the same time providing a definite fuel control dependent upon engine conditions. l My invention will be more readily understood by reference to the accompanying drawings, in which- Figure 1, more or less diagrammatically illustrates the preferred form; and i Figure 2 illustrates that form of my inventlon wherein afloat chamber is employed. Referring first to Figure 1, it will be seen that the carbureting chamber is formed by the provision of a generally tubular member 3 to which air is admitted at the bottom 2 where a hot air pipe ma be connected, if desired. A bridge or spi er 4 extends transversely across the tubular member 3 and supports the primary VenturiA tube 5,

the member 1 being provided with passageways 6, ,6, through which air may pass upwardly around the Venturi tube 5. The Venturi'member 5 is provided with an annular. groove 7 which, when the tube is inserted tube 11 which'is arranged to surround the primary Venturi tube l5 and which is adjustable from its uppermost position, shown approximately in full line, to its lowermost position, shown in dotted line.

In the wall of the member S'there is provided a longitudinal slot 12 through which a pin 13, set into the secondary tube 11, extends, a wire 14 being secured to this pin and passing on to an operators position, in an automobile for instance, to a fiexible wire guide 15. By means of suitable adjusting mechanism on the steering column, for instance, the operator is enabled to move the second Venturi tube 11 up and down between the two positions noted. It will bey seen that when the member 11 is in its lower most position, shown in dotted line, it closes off the passageway surrounding the primary Venturi tube 5 and confines all the air entering the carburetor and passing on to the engine to the smaller primary Venturi tube 5. In this way the desirable rich mixture for starting is obtained. For subsequentf innedr Venturi tube may be effectively regulate Above the Venturi tube 11 the usual butterfly throttle 16 is provided, being mounted upon the transverse shaft 17 which, as usual, is under operators control. At the top of the tubular member 3 there is provided the usual flange 18 for attachment to the flange 19 of the manifold 20, by means of bolts 21, 21, the manifold being, of course, provided in the case of a multi-cylinder engine but it beingA understood that my invention can also be employed in connection with a single cylinder engine.

' Coming now to the gasoline supply, it will be seen that the pipe 10 leads from the bottom, or near the bottom of a cu 22, the bot; tom of which is in the form of a union 23, from which a nozzle 24 extends upwardly into the cup, the nozzle 24 being in axial alignment with the cup, as shown. The nozzle 24 has the youtlet 25 at the top and the cup has the atmosphere inlet 26 at the top thereof. A needle valve stem 27 is fitted for reciprocation within the nozzle .24 and terminates in a reduced needle valve 28 which extends into the outlet 25 and which, upon vertical movement, varies the effective size thereof. As shown, the needle valve 28 is in its lowermost position.

Mounted upon the union 23 in axial alignment with and below the cup 22 is a cylinder 29 in which there is lprovided a piston 30 secured to the bottom of the valve stem 27. The piston 30 is provided with a downward facing shoulder 31 between which and the bottom of the cylinder 29 a helical spring 32 is disposed. The piston 30 is provided with a passageway 33 therethrough, this passageway being controlled by a downwardly opening check valve 34. There is also a passageway 35 provided through the valve stem 27 and the piston 30, this passageway being controlled by an upwardly opening check valve 36, and being thus arranged to connect the chamber below the i piston and -the interior of the nozzle 24. A

fuel pipe 37 feeds into the cylinder 29 above the piston 30 and leads directly from a main lsupply tank 38 containing liquid'fuel.- A

check valve 39 is provided in this fuel pipe, this valve bein overcome by the head of liquid fuel but lieing there to prevent back flow of the fuel.

A cylinder 39 has its bottom 40 screwed into the` top of the cup 22, the bottom 40 providing a central bearing for the reciprocating plunger 41 to which the piston 42. mounted for operation in ,the cylinder 39, is secured. The plunger 41, as shown, extends down into' the cup 22 'and has a beveled end which, as illustrated, is adapted toseat upon the nozzle 24, absolutely closing the outlet 25 thereof, when the piston 42 is in its lowerf most position. As a matter of convenient construction, the lowerv end of the plunger 41 is provided with a small pocket in which the needle valve 28 extends, the needle valve and the plunger thus operating together. A spring 43 extends between the top of the cylinder 39 and the piston 42, this spring being stronger than the spring 32. Atmosphere is admitted tothe bottom of the cylinder 39 by way of a passageway 44 and the top of the cylinder is connected to the mani# fold 20 by means of a pipe 45, so that the subnormal pressure in the manifold will be effectiveyin the cylinder 39 over the piston 42.

A small cylinder 46 is mounted upon the piston 42, conveniently forming a clamping member between which and the shoulder 47 on the plunger 41 Lthe piston 42 is secured. The cylinder 46 is closed at the top by means of a member 48 and a piston rod 49 mounted in the member 48 and within the cylinder 46 has secured thereto a piston 59 fitting into the cylinder 46 insuch a way as to leave sufficient by-pass to permit proper by ,means of suitable connecting linkage.

goes to an operators position.

It will now be seen thatwith the subnormal pressure of the manifold during running condition effective on top of the piston 42 with atmosphere effective below it,

the piston 42 will tend to rise against the tension of the spring 43, and the spring 43 is, of course properly chosen for this purpose. When there is no subnormal pressure in the manifold, the piston 42, of course,

'lies at its lowermost position and there, as

has been pointed out, the lower end of -the plunger 41 absolutely closes ofi' the outlet 25 from the nozzle 24,'th'us, although there is a constant head or at least continuous head of asoline tending to move out of the nozzle,t e entire system is at rest, and in this way the use of a lot chamber is entirely dispensed with.

Let it be assumed now that the engine is started with the butterfly throttle 16, say, in lmid-position. There is, of course, a considerable difference in pressure above and bel'ow the butterfly throttle 16, but it will be noted that the pressure to which the piston 42 is subject is thatl above or on the engine side of the throttle 16. The piston 42 therefore rises against the tension of the spring` 43 to the position balancing this subnormal pressure. lThe plunger 41 rising with the piston 42 thus opens ila the outlet 25 of the nozzle 24 immediately, 130

throwing' thecontrol of that nozzlemutlet onto the needle valve-28,' which, as has been 'described, followsl the piston .42 in its up-` Ward motion,duegto` theV extension. of the 51 spring 32 under` the piston' 30. It will be 'seen therefore that under'these conditions :liquid fuel-'hasj free passage from)` the mainw tank38 through the pipe 37 past the check valve 39 linto 'the cylinder 29 above the pis- 1.0ton= 30 ldown through4 the passageway 33 'the subnormal pressure inthe manifold l20.

'llhefmovement of 'the 'piston 42 is made .gradual and eEectiye -`to predominating pressures -by the dashpot action between moved beck and forth, gas 1n the case ofthe usual running ofianautomobile, the? sub.

normal pressure 'incth'e manifold .WillfI .vary

and-the piston- 42; will respondtothese, thefnee'dle valve28'acu Variations, movin 3,5 cordingly, gradlra ly, reducili slightlythe size of passageway'25 ast ef' suction ...im -creases 1n`order to counteract the tendency fof the mixture .tofgrow` toorich under lsuch` circumstances;

j Referrin ifi-110W ation, it wlll clearl that when the throttle '16 is nearly' closed,as'on low running, and is thensuddenly opened, the vacuum in the manifold 20 `will, break,- This means4 that -the piston 42Will cdrop suddenly, 'not all the'way, but just-enough to respond to the condition,. th1s action resulting in ;the pumping of thepocketed supply of liquid` Y nel below the piston @upwardly/through' 5@ the passageway '35 and out of thezf nozzle `v24 as an increment tothejo'rdinary runningl supply ot asoline. lt-,will be clear that the' supply ofiquidfuel in the way of-this increme'nt is de endent upon the extent 'of Tttc- Aceleration. et it ,be assumed that a cerxtain accelerationfis made which will pum out half the accumulated su ply-below the -v piston 30, lfthereupon .a ur'ther acceleri4 lation 'should be made theepiston 30 will` l simply come down further. with' .its proper and eiective .supplemental increments,

'Let it'befassumednowthat-the en ine fis 1 stopped, by cuttigio the ignition, 'flor iii- "'stance It will be clear that lthe pressure in the manifold v2() will rise atmosphere Vthat in this form itis not necessary that the ,cases we, have the starting supplyl of liquid f as'a primary mixing chamber in which the lin that way cup and the piston 42 will go down 'to its low-- ermost position absolutely closing off the nozzle outlet 25, returning to the pointl assumedv at the'beginning of the description of operation. lt will be kept in mind here that with the closing od of this nozzle outlet 25 there is -a certain amount 'of liquid fuel beyond the controlI of the plunger 41 and this amount is trapped in the cup 22 around the nozzle, as illustrated, ready as 75 an ,enrichin supply-for starting purposes. lt-is desirable to be able to adjust the extent to which the range of movement -of the istonl 42 travels. It will be seen that by t e, action of the cam '53 the upward, 80 movement'of the piston is limited by the engagement of the' bottom ofthe cylinder '46 with the piston 50, thus determinin `minimum suction opening at 25 for igh running. 0n the other hand, the piston 50 85- the may, on occasion, lbe made to engage the top of thecylinder 46 so as to limit the down? ,wardg movement of the piston 42.

-Figure 2 is precisely like Figure 1, except that a loat'chamber of any conventional type, indicated at 60, intervenes be- Jtween the pipe 37 and :the mainsupply of liquid fuel. The level of gasoline is maintained on the'line lt will be clear plunger 4l shall ever absolutely close the lpassageway 25 out of the nozzle 24 and in fact the" control of the passageway 25 lies" always with the needle valve 28. ln both fuel in addition ito the regular supply, this extra supply being promptly exhausted up on starting whereupon the cup 22 operates gasoline is .broken up to a great extent by the'aii entering the opening 26. When the engineis'stopped the last stroke or two is suicient to raise fuel out of the nozzle but isinsufficient to carryit to the manifold, and

' 22 is refilled.' H0 lllclaim:

Y1, :ln combination, a carbureting chamber havin a fuel nezzle. and' an .air supply, a

-thrott e controlling the outlet from said chamber, said outlet being adapted to be Iconnected to an internal combustion engine, means for controlling Ymeans belng governe the `i'uel supply, said by the pressure on the engine side of said-throttle, normally cuttingjoi'the'full-supply and when opened operating to decrease theproportion-of fuel as 'the ,suction increases, and means operated 'by rst said means orinjecting fuel to the fuel -no'z-zleupon starting.

.2. ln combination', a' carbureting chamber having fuel and air supplies, a throttle con- `trolling the outlet from said "carbureting ',chambe'r, said-'outlet being adapted to be -connected to an internal combustion engine, la reservoir for 'liquid fuel connected'to said fuelsupply, a cut-off valve closing said connection when there is no suction, means sub'- ject to the pressure on the engine side of the throttle for opening said cut/off valve when suctionv begins, and means connected with said valve for injecting apsupply of gasoline upon a drop in suction.

3. In combination, avcarburetingchamber having fuel and air supplies, -athrottle controlling the outlet from said carbureting chamber, said outlet being adapted to be connected to an internal combustion engine, a reservoir for liquid fuel connected to said fuel supply, a cut-off valve controlling said connection, al needle valve controlling said fuel supply, inversely to the suction means subject to the pressure on the engine side of the throttle for operating saidcut-o' valve and said needle valve, and means connected with first said means operable to enhance the fuel feed upon a drop in pressure.v

4.' In combination, a carbureting chamber having airo and fuel inlets and" a mixture outlet, a throttle for said outlet, said outlet being adapted to be connected with an internal combustion engine, a fuel reservoir having the liquid level therein above said fuel inlet and connected with said fuel inlet,

starting.

5. In combination, a carburet'ing chantber having air and fuel inlets andf a mix- 4ture outlet, a throttle for said outlet, said l outlet being adapted to be `connected with an internal combustion engine, a fuel reservoir having the liquid level, therein above said fuel inlet and' connected with said fuel inlet, a cylinder, a piston operating in said cylinder, a cut-off valve'for said fuel 'connection operating with said piston, aconnection between said cylinder on one side of said piston and the engine side of the throt- `der operable-by said' needle valve for temporarily increasing the flow of fuel.

V6. In .combination` a carbureting chamber having air and fuel inlets and a Amixture outlet, a throttle for said outlet, said outlet being adapted to be connected with an internal combustion engine, a fuel reservoir having the liquid level therein above said fuel inlet and connected with said fuel inlet, a cylinder, `a piston operating in said cylinder, a cut-off valve for said fuel connection operating with said piston, a connection between said-cylinder on one side of said piston and the engine side of the throttle, said piston being moved to open said cut-off valve upon creation of subatmospheric pressure on the engine side of said' throttle, a needle valve for-controlling said fuel con- 'nectiom said needle valve' operating with said piston, a secondary cylinder and means for trapping an auxiliary supply of fuel in said secondary cylinder, and a piston operating in said secondary cylinder with said first-named cylinder for pump-ing the trapped fuel from said secondary cylinder. In witness whereof, I hereunto subscribe my name this 22nd day of December A; D. 1916. Y

GEORGE B. MAEGLY. 

